Exfoliative Cytology in the Diagnosis of Ocular Surface Squamous Neoplasms

Surface tumors of the eye comprise an ample spectrum of diseases with various clinical manifestations. Diagnosis has been traditionally achieved through core biopsies, but cytology is an innovative, fast, and minimally invasive method. The objective of this study was to investigate the use of exfoliative cytology as an alternative method for the detection of ocular surface squamous neoplasm (OSSN).

Exfoliative cytology of the lesions was performed by collecting smears using plastic brushes followed by smearing the cells onto slides and subsequently fixing them in 90% alcohol. Incisional biopsies were performed at the exact same location and sent for processing in 10% formaldehyde. Both the surgical pathologist and cytopathologist were masked to the clinical characteristics and to the corresponding cytological or histological result.

Twenty-two patients were enrolled in the study (12 men and 10 women, median age 52.5 years). Final histological diagnoses comprised 7 cases of pterygium, 7 squamous-cell carcinomas, 4 squamous papillomas, and 4 chronic inflammatory processes. Cytohistological agreement was achieved in 19 (86.4%) of the samples. Cytology showed a sensitivity, specificity, positive predictive value, and negative predictive value of 85.7%, 86.7%, 75%, and 92.9%, respectively, in detecting OSSN.

Exfoliative cytology of the conjunctival lesions is a simple procedure, with high agreement to the histological follow-up. Its broad use could augment the early diagnosis of OSSN, with improvement in patient prognosis.